getGenericParameterTypes Scala 2.13.0-RC2

Main.scala

object A {
  trait B {
    // include outer param in getGenericParameterTypes
    case class C1(a1: Int)
    case class C2(a1: String)
    case class C3(a1: Array[Int])

    // NOT include outer
    case class C4(a1: Option[Int])
    case class C5(a1: List[Int])
    case class C6(a1: Option[String])
  }

  object D extends B
}

object Main {
  def f[X](implicit x: reflect.ClassTag[X]): String = {
    x.runtimeClass.getConstructors.head.getGenericParameterTypes.toList.toString
  }

  def main(args: Array[String]): Unit = {
    println(scala.util.Properties.versionString)

    assert(f[A.D.C1] == "List(interface A$B, int)")
    assert(f[A.D.C2] == "List(interface A$B, class java.lang.String)")
    assert(f[A.D.C3] == "List(interface A$B, class [I)")
    assert(f[A.D.C4] == "List(scala.Option<java.lang.Object>)")
    assert(f[A.D.C5] == "List(scala.collection.immutable.List<java.lang.Object>)")
    assert(f[A.D.C6] == "List(scala.Option<java.lang.String>)")
  }
}